1. Field of the Invention
This invention relates to a method of selecting an advertisement to be shown to a user based on the content files selected and viewed by a user. More particularly, this invention relates to determining an affinity measure between an advertisement and a set of content files.
2. Background of the Invention
Product advertisement in media such as newspaper and television have the advantage of reaching many people. At the same time, these forms of advertisement are indiscriminate and may reach many people who are not interested in the product advertised.
An advertisement is more effective when it can be targeted to a specific market that is more likely to be interested in the product advertised. For example, advertisements for fishing equipment will be more effective when placed in a fishing magazine.
On the world-wide web (WWW), advertisers can target specific markets with more discrimination than other media. The manner in which content is presented on the WWW means that advertisers can reach increasingly well-defined segments of the market. For example, a high percentage of people who access a stock quotes WWW page may be interested in a stock broker. A stock broker who places an advertisement on this WWW page mall reach a smaller group of people, but a much higher percentage of this group will be potential customers. This is in stark contrast to other media such as newspaper and television, in which the target market may only be a small percentage of the total market reached.
Other media, including emerging and developing technologies such as on-demand television, will also give advertisers similar ability to target specific markets.
To take advantage of this ability to target specific markets on the WWW, advertisers often estimate a user's interests using a variety of profiling techniques. These profiling techniques can help an advertiser to select an advertisement to present to the user. Current profiling techniques use a combination of demographic, geographic, psychographic, collaborative filtering, digital identification, and hypertext transfer protocol (HTTP) information. However, these current techniques have met only with limited success.
What is needed is a more sophisticated profiling technique for generating a more useful user profile. This more useful user profile would be valuable in selecting an advertisement to be shown to the user.